Rotary fluid engine

ABSTRACT

A rotary fluid engine consisting of a cylindrical housing having a normally fixed sun gear mounted axially therein, a hollow piston carrier mounted for axial rotation in the housing and divided intermediate its ends into two independently rotatable sections, and defining an annular chamber in conjunction with the housing, each section of the carrier fixedly supporting a pair of diametrically opposite pistons each filling the cross-sectional contour of the chamber, a flywheel disposed rotatably within the hollow carrier and directly connected to the power output shaft of the engine, the housing having inlet and exhaust ports for admitting fluid under pressure into the chamber between diametrically opposite pairs of pistons to urge the associated pistons in relatively opposite directions, and exhaust ports for exhausting the fluid from the chamber after a pre-determined motion of the pistons, a pair of planetary gears meshed with the sun gear at diametrically opposite points and carried rotatively by the flywheel, and a crank and link arrangement connectingeach planetary gear to one of the sections of the connecting each so arranged that fluid pressure in opposite directions on the pistons associated with either inlet port is operative to act through the planetary gears to turn said fly-wheel and power output shaft in a single direction.

United States Patent [191 Goering ROTARY FLUID ENGINE [75] Inventor: Dan H. Goering, Shawnee, Kans.

[73] Assignee: Peterson Machine Tool, Inc.,

Merriam, Kans. a part interest [22] Filed: Dec. 22, 1972 [21] Appl. No.: 317,792

Related U.S. Application Data [63] Continuation-impart of Ser. No. 189,676, Oct. 15,

Prim ary Examiner-C. .l. Husar Attorney, Agent, or Firm-.lohn A. Hamilton Aug. 13, 1974 57 ABSTRACT A rotary fluid engine consisting of a cylindrical housing having a normally fixed sun gear mounted axially therein, a hollow piston carrier mounted for axial rotation in the housing and divided intermediate its ends into two independently rotatable sections, and defining an annular chamber in conjunction with the housing, each section of the carrier fixedly supporting a pair of diametrically opposite pistons each filling the cross-sectional contour of the chamber, a flywheel disposed rotatably within the hollow carrier and directly connected to the power output shaft of the engine, the housing having inlet and exhaust ports for. admitting fluid under pressure into the chamber between dia-' metrically opposite pairs of pistons to urge the associated pistons in relatively opposite directions, and exhaust ports for exhausting the fluid from the chamber after a pre-determined motion of the pistons, a pair of planetary gears meshed with the sun gear at diametrically opposite points and carried rotatively by the flywheel, and a crank and link arrangement connectingeach planetary gear to one of the sections of the connecting each so arranged that fluid-pressure in opposite directions on the pistons; associated with either inlet port is operative to act through the planetary gears to turn said fly-wheel and power outputshaft in a single direction.

7 Claims, 6. Drawing Figures This application is a continuation in-part of my prior co-pending US. Pat. application Ser. No. 189,676, filed Oct. 15, 1971, which will become abandoned as of Jan. II, 1973.

This invention relates to new and useful improvements in fluid engines, such engines being of a class operable to convert the internal energy of pressurized fluids, either gas or liquid, into rotary mechanical energy delivered by a rotating shaft.

The principal object of the present invention is the provision of a rotary fluid engine which is highly corn pact and light in weight in proportion to its power capacity.

Another object is the provision of an engine of the character described including an annular pressure chamber in which are disposed four movable pistons, diametrically opposite pairs of said pistons being rigidly fixed together, means for introducing fluid under pressure into said chamber at diametrically opposite points and for exhausting said fluid at angularly offset diametrically opposite points, and means connecting said pistons to a power output shaft whereby when fluid is introduced into said chamber between angularly adjacent pistons and said pistons therefore are moved in relatively opposite directions, the movement of both is converted to a unidirectional torque driving said output shaft.

A further object is the provision of an engine of the character described wherein said means connecting said pistons to said output shaft is disposed entirely within the annulus of said pressure chamber, whereby to produce a highly compact engine.

A still further object is the provision of an engine of the character described wherein said means connecting said pistons to said output shaft includes a fixed sun gear, a planetary gear carried rotatably by said output shaft, in radially offset relation therefrom, and meshed with said sun gear, a pair of diametrically opposite cranks fixed to and rotatable with said planetary gear, and a pair of links each pivoted at one end to the free end of one ,of said cranks, and at its opposite end to one of said pairs of pistons, said links, except in a dead center position, always being disposed in angularly opposite offset relation relative to a dead center position relative to their cranks, whereby both cranks deliver torque to said planetary gear, in the same direction, when fluid is introduced between any angularly successive pair of pistons.

Other objectsare simplicity and economy of construction, and efficiency and dependability of operation.

With these objects in view, as well as other objects which will appear in the course of the specification, reference will be had to the accompanying drawing, wherein:

FIG. 1 is an axial sectional view of a rotary fluid engine embodying the present invention, prepared to show structure only, various parts being shown out of position and in incorrect proportions, V

FIG. 2 is a sectional view taken on line ll-II of FIG. 1, with the parts in correct proportions and positions, shown at the beginning of one of the four cycles of operation involved in one full turn of the power output shaft,

FIG. 3 is a reduced, partially diagrammatic view similar to FIG. 2, but showing the parts in the positions assumed thereby substantially at the completion of the powered phase of the cycle of operation beginning at the FIG. 2 position,

FIG. 4 is a view similar to FIG. 3, but showing the parts in the positions assumed thereby at the comple tion of the cycle of operation begun at the FIG. 2 position, and ready for commencement of the next subsequent operative cycle,

FIG. 5 is a forward end view of the engine, and

FIG. 6 is an enlarged fragmentary sectional view taken on line VIVI of FIG. 5.

Like reference numerals apply to similar parts throughout the several views, and the numeral 2 applies generally to the housing of the engine. Said housing is hollow and generally cylindrical, having a cylindrical peripheral wall 4 and generally planar front and rear end walls 6 and 8 secured to said peripheral wall by screws 10. A shaft 12 extends axially through the housing, and outwardly from both ends thereof, and establishes the engine axis. Said shaft is rotatable, being journalled in front wall 6, but is normally fixed against rotation by an arm 14 keyed thereto outwardly of front end wall 6. Said arm extends radially, and its outer end is confined between the ends of a pair of opposed screws 16 threaded in bosses l8 affixed to or integral with wall 6, as best shown in FIGS. 5 and 6. Fixed axially on shaft 12, within the housing and midway between the housing end walls, is a sun gear 20, said sun gear of course also being normally fixed and non-rotating.

The engine also includes a flywheel indicated generally by the numeral 22, rotatable on shaft 12. Said flywheel also serves as a carrier for the planetary gears to be described. Said flywheel is shown as constituting two heavy discs 22A and 22B, disposed respectively at opposite sides of sun gear 20, connected together to form in effect a single unitary flywheel by a pair of planetary gear shafts 24 extending through both of discs 22A and 22B, and rotatably mounted therein. These shafts are disposed outside the perimeter of sun gear 20, and at diametrically opposite sides of shaft 12. Between flywheel discs 22A and 228, each shaft 24 has a planetary gear 26 affixed thereto and meshed with sun gear 20. The pitch diameter of each planetary gear 26 is one-half of the pitch diameter of the sun gear. A crank 28 is affixed to each end of of each shaft 24. Said cranks are disposed at the distal sides of discs 22A and 22B, and are disposed in opposed relation, being angularly spaced apart by degrees. Also, the cranks 28 at the corresponding ends of each of the two shafts 24, that is, the two cranks adjacent disc 22A and the two cranks adjacent disc 22B, are disposed 180 out of phase, and are maintained in this relationship at all times by the engagement of planetary gears 26 with sun gear 20.

Flywheel disc 22B is provided with an integral axial extension 30 which extends outwardly through rear end wall 8 of the housing, being journalled therein, and constitutes the power output shaft of the engine, a gear 32 or other power delivery device being fixed thereon externally of the housing. Extension 30 is tubular, and shaft 12 extends therethrough and is journalled therein.

Mounted within housing 2, and rotatably journalled on shaft 12 and power output shaft 30, adjacent end walls 6 and 8 of the housing, is a piston carrier indicated generally by the numeral 34. Said carrier is also hollow and cylindrical in form, having end walls 36 and 38 disposed respectively adjacent housing end walls 6 and 8 with thrust bearings 40 therebetween, and a cylindrical peripheral wall 42. As indicated at 44 the carrier is split midway between its ends and normally to the engine axis, into two halves 34A and 34B which can rotate independently. Any suitable seal, not shown, may be provided at split 44 to prevent fluid leakage between the carrier halves. The diameter of peripheral wall 42 of the piston carrier is less than the diameter of peripheral housing wall 4, so as to form an annular pressure chamber 46 therebetween. Fixed to each carrier half 34A and 343, as by screws 48, are a pair of diametrically opposite pistons 50, each piston occupying substantially the entire cross-sectional area of chamber 46, although suitable seals, not shown, may be provided between each piston and the housing walls and between each piston and the half of carrier 34 to which that piston is not affixed. However, it will be appreciated that by making the pistons of considerable angular extent, 22 /2 as shown, fluid leakage by-passing the pistons must occur through long, very narrow passages, and is consequently reduced. This in large measure alleviates the sealing problems which commonly plaque engines of this general type. For convenience, the two pistons affixed to forward carrier half 34A are further designated A and B, and the pistons affixed to rear carrier half 34B are designated C and D.

The respective end walls 36 and 38 of the carrier halves 34A and 34B are each connected to the corresponding cranks 298 by links of equal length. That is, each of the forward cranks 28 is connected to end wall 36 of front carrier half 34A by a link 52, and each of the rear cranks 28 is connected to end wall 38 of rear carrier half 348 by a link 54. Each link is pivoted to the free end of its associated crank 28 at 56, and to its associated carrier end wall 36 or 38 at 58, the axes of all of said pivots being parallel to planetary gear shafts 24 and to the engine axis. The length of the links is not particularly critical, although their lengths should all be equal, and the length of each is preferably somewhat greater than the pitch diameter of each planetary gear 26. However, the spacing of pivots 58 from the engine axis is quite critical, and must be such that in completing one full orbit around the power output shaft, each pivot 58 will cause its associated link to turn the associated planetary gear about its axis a number of times precisely equal to the ratio of the pitch diameter of the sun gear to the pitch diameter of the planetary gear, or two full turns in the example illustrated, since the sun gear and the planetary gears have a 2 to 1 ratio. This relationship is necessary in order that the pistons will maintain a proper relationship to the inlet and outlet ports to be described. The pivots 58 of each carrier half are disposed in diametrically opposite relation, those of front carrier half 34A being disposed 90 out of phase with the pistons A and B carried thereby, and those of rear carrier half 348 being angularly aligned with its pistons C and D.

In describing the operation of the engine, reference will first be had to F IG. 2, which shows the parts in their correct proportions and positions for thebeginning of the powered phase of one of the four cycles of operation necessary to complete one full turn of output shaft 30. The connection of front links 52 to pistons A and B is indicated by dotted lines 62, and the connection of rear links 54 to pistons C and D is indicated by dotted lines 64. At the FIG. 2 position, forward links 52 are each closely adjacent an extended dead center position relative to their cranks 28, but with the crank-link connections 56 buckled radially outwardly from said dead center positions, while rear links 54 are closely adjacent a retracted or jack-knifed dead center position with respect to their cranks 28, but with the crank-link connections buckled radially inwardly from said dead center positions. The direction of engine rotation is indicated by arrow 60. Rotation of planetary gears 26 around sun gear 20 tends to produce opposite rotation of the two sets of pistons, forward rotation of pistons A and B and rearward rotation of pistons C and D, but at this time very little relative rotation of the two sets of pistons occurs, and they turn nearly in unison, due to the near dead-center positions of the linkages. At this moment, pistons A and B are just beginning to uncover a pair of diametrically opposite inlet ports 66 formed in peripheral wall 4 of the housing, whereby gas or other fluid under pressure is admitted to the sections of pressure chamber 46 between pistons A and C, and between pistons B and D.

The pressure thus applied of course tends to move pistons A and B forwardly in the direction of arrow 60, and to move pistons C and D in the opposite direction. The forward movement of pistons A and B is transmitted through front carrier section 34A, links 52 and front cranks 28 to turn planetary gears 26 in a clockwise direction, as viewed in FIG. 2, thereby forcing said planetary gears to travel in a clockwise direction around sun gear 20, this movement acting through planetary gear shafts 24 and flywheel 22 to turn power output shaft 30 in the same direction. At the same time, due to the opposite buckling of rear links 54, as shown in FIG. 2, the reverse pressure on pistons C and D also forces the planetary gears to turn in a clockwise direction around the sun gear, so that these pistons, though loaded in a direction reverse to the engine rotation, also supply a forward drive to the output shaft. Actually, during this power stroke, pistons C and D do not move in a reverse direction, but in fact advance slightly, the relative rearward movement of these pistons being nearly but not entirely offset by the advancement of the associated planetary gear, and by the extension of links 54 relative to their cranks 28. During this power phase, spent gases ahead of pistons A and B are exhausted through a pair of diametrically opposite exhaust ports 68.

The above described power phase continues until pistons A and B have advanced about this representing an advance of the planetary gears of about 60 around the sun gear, and a correspo nding rotation of about of the planetary gears about their own axes. This position is shown in FIG. 3. Pistons A and B are at that time just covering exhaust ports 68, while pistons C and D have advanced only slightly, not enough to cover inlet ports 66. The limitation of about 90 to each power phase of each piston is necessary since this represents the maximum movement in which an effective working angle between the links and cranks can be maintained. Beyond that point the links and cranks are approaching a reverse dead center position, so that the links could exert very little torque on the cranks. Also, both sets of pistons are then moving substantially in unison, due to the near dead center positions of the cranks. Therefore, during the next approximately 45 movement of the pistons, representing about 30 of movement of the planetary gears around the sun gear and about 90 of rotation of the cranks, the pistons are moving in unison and must be moved by the inertia by flywheel 22, and the parts are moved to the FIG. 4 position. During this movement, it will be seen that pistons C and D cover inlet ports 66 before pistons A and B uncover exhaust ports 68, so that there can be no blowthrough and wastage of fluid, and all of the link-crank assemblies move through their dead center positions to an opposite operative position, links 52 then having a retracted position rather than extended as in FIG. 2, and links 54 having an extended position rather than retracted as in FIG. 2. Pistons C and D will then be starting to uncover the inlet ports 66, exhaust ports 68 then being open, with the output shaft and planetary gears having advanced 90 relative to the sun gear, pistons A and B having advanced 135, and pistons C and D having advanced 45. The pistons then have the same overall relation as in FIG. 2, except that each has advanced one position in the progression. That is, from the upper inlet port, the piston order in FIG. 2 is A-D- B-C, while in FIG. 4 the progression is C-A-D-B. This marks the completion of one full operative cycle of the engine, and the next cycle is ready to begin. Said next cycle is identical to the cycle just described, except that in the next cycle, pistons C and D then apply forward torque by their forward movement, with their links 54 operating in compression rather than in tension as in the previous cycle, while pistons A and B apply forward torque by the reverse pressure exerted thereon as did pistons C and D in the previous cycle, with links 52 acting in tension rather than in compression as before. On completion of four cycles as described, the engine will have completed one full revolution, and all parts will have returned to the FIG. 2 position, and operation in like manner of course continues indefinitely as long as fluid is supplied to the engine. It will be thus seen that for each full revolution of power output shaft 30, it will be supplied with power in four 60 degree increments, and that it will be moved by the inertia of the flywheel in four alternating 30 degree increments.

There is of course the possibility that when fluid supply to the engine is terminated, it will come to rest with inlet ports 66 covered, and with the crank-link combinations in or substantially in dead center positions, so that it cannot be re-started simply by re-establishment of the fluid supply. If this occurs, screws 16 may be loosened and arm 14 turned slightly. This turns sun gear 20 which then turns the planetary gears 26 to advance the pistons to uncover inlet ports 66 so that the engine will start. Arm 14 can then be returned to its normal position. In many cases this eliminates the necessity for any auxiliary starting motor, which has often been required for engines of this general type. Also, adjustment of the timing of the engine by means of arm 14 affects the speed and efficiency of the engine under differing degrees of loading.

' Thus it will be apparent that a fluid engine having several advantages has been produced. The engine has a high ratio of power output to its size and weight. A good power ratio is obtained by the l to 2 ratio of the planetary gears to the sun gear, in that while the pistons are actually delivering torque for a full 360 of their own movement, this powered movement is reduced to only about 240 of each revolution of the power output shaft. By increasing the ratio of the gears, a still greater power factor may be obtained. The location of the pistons in a peripheral chamber of large diameter provides very good leverage for their application of torque to the output shaft, and their resulting long movement for each shaft rotation contributes to smoothness of opera tion. The inclusion of the flywheel, crank and link assembly within the hollow interior of the pressure chamber provides an extremely compact engine, with a high ratio of power output to its size.

While I have shown and described a specific embodiment of my invention, it will be readily apparent that many minor changes of structure and operation could be made without departing from the spirit of the invention. For example, while two planetary gears are shown, each with its own cranks and links, it will be apparent that each of the front links 52 is at all times precisely duplicating the action of the other, and that the same is true of the two rear links .54. Therefore, the engine would operate with only one planetary gear, with one front link and crank, and one rear link and crank. However, the use of two planetary gears, with their associated links and cranks, keeps both the weight and torque balanced at all times relative to the engine axis, and is preferred.

What I claim as new and desire to protect by Letters Patent is:

1. A rotary fluid engine comprising:

a. a housing,

b. a rotatable power output shaft concentric with said housing,

c. means defining an annular pressure chamber in the peripheral portion of said housing,

(I. four pistons mounted in and angularly movable in said pressure chamber, diametrically opposite pairs of said pistons being rigidly fixed together,

e. an inlet port for introducing; fluid under pressure into said chamber whereby said pistons are moved angularly in said chamber,

f. an exhaust port for exhausting fluid from said chamber at a point angularly offset from said inlet port, and connecting means joining said pistons to said output shaft whereby movement of the former produces rotation of the latter, said connecting means comprising a cylindrical piston carrier defining the interior wall of said pressure chamber, and divided into two sections journalled for independent rot'ation coaxially with said output shaft, said pairs of pistons being affixed respectively to one of said carrier sections, a sun gear normally fixed in said housing coaxially with said output shaft, a planetary gear carrier affixed to said output shaft and rotatable therewith, a planetary gear journalled in said planetary gear carrier eccentrically to said output shaft and meshed with said sun gear, a pair of angularly opposite cranks affixed to said planetary gear and rotatable therewith, and a pair of links each of greater length than the radius of said planetary gear, each link being pivoted at one end to the free end of one of said cranks and at its opposite end to one of said piston carrier sections, all of said crank pivots being parallel to said output shaft. 2. A rotary fluid engine as recited in claim I wherein said planetary gear carrier constitutes a heavy flywheel affixed to and concentric with said output shaft.

3. A rotary fluid engine as recited in claim 1 wherein each of said links is pivoted to its associated piston carrier section at a distance from the output shaft axis such that in completing one full revolution about said output shaft, said planetary gear will be caused to rotate about its axis a number of times precisely equal to the ratio of the pitch diameter of the sun gear to the pitch diameter of theplanetary gear.

4. A rotary fluid engine as recited in claim 3 wherein one of said links is pivoted to its associated piston carrier section at a position, relative to the pistons carried by that carrier section, ninety degrees out of phase with the connection of the other link to the other piston carrier section, relative to the pistons carried by said other carrier section.

5. A rotary fluid engine as recited in claim 4 wherein said inlet ports are positioned, angularly of said housing, to be uncoveredby a pair of said pistons when said cranks are adjacent, but angularly offset from a dead center position relative to their links, and said exhaust ports are covered by the same pair of pistons before said cranks have turned 180 degrees from the first posi- Hon.

6. A rotary fluid engine as recited in claim 1 including a pair of said planetary gears, disposed diametrically opposite each other relative to said sun gear, each of said planetary gears carrying a pair of said cranks and links, the cranks of the respective planetary gears associated with each of said piston carrier sections being disposed 180 out of phase with each other.

7. A rotary fluid engine as recited in claim 1 with the addition of means whereby said sun gear may be adjustably turned relative to said housing.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 5 357 Dated August 13, 1974 Inventor(s) Dan rlng It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

In the Abstract, line 20; "connectin should read conneccing line 21, "geach" should read each lines' 22 and 23 "connecting each" should read carrier,

Signed and sealed this 3rd. day of December 1974.

(SEAL) Attest:

McCOY M. vGIBSON JR. Attesting Officer 0. MARSHALL DANN Commissioner of Patents FORM po-mso (ID-69). i USCOMMDC 6037mm U,S. GOVERNMENT PRINTING OFFICE: 9 93 

1. A rotary fluid engine comprising: a. a housing, b. a rotatable power output shaft concentric with said housing, c. means defining an annular pressure chamber in the peripheral portion of said housing, d. four pistons mounted in and angularly movable in said pressure chamber, diametrically opposite pairs of said pistons being rigidly fixed together, e. an inlet port for introducing fluid under pressure into said chamber whereby said pistons are moved angularly in said chamber, f. an exhaust port for exhausting fluid from said chamber at a point angularly offset from said inlet port, and g. connecting means joining said pistons to said output shaft whereby movement of the former produces rotation of the latter, said connecting means comprising a cylindrical piston carrier defining the interior wall of said pressure chamber, and divided into two sections journalled for independent rotation coaxially with said output shaft, said pairs of pistons being affixed respectively to one of said carrier sections, a sun gear normally fixed in said housing coaxially with said output shaft, a planetary gear carrier affixed to said output shaft and rotatable therewith, a planetary gear journalled in said planetary gear carrier eccentrically to said output shaft and meshed with said sun gear, a pair of angularly opposite cranks affixed to said planetary gear and rotatable therewith, and a pair of links each of greater length than the radius of said planetary gear, each link being pivoted at one end to the free end of one of said cranks and at its opposite end to one of said piston carrier sections, all of said crank pivots being parallel to said output shaft.
 2. A rotary fluid engine as recited in claim 1 wherein said planetary gear carrier constitutes a heavy flywheel affixed to and concentric with said output shaft.
 3. A rotary fluid engine as recited in claim 1 wherein each of said links is pivoted to its associated piston carrier section at a distance from the output shaft axis such that in completing one full revolution about said output shaft, said planetary gear will be caused to rotate about its axis a number of times precisely equal to the ratio of the pitch diameter of the sun gear to the pitch diameter of the planetary gear.
 4. A rotary fluid engine as recited in claim 3 wherein one of said links is pivoted to its associated piston carrier section at a position, relative to the pistons carried by that carrier section, ninety degrees out of phase with the connection of the other link to the other piston carrier section, relative to the pistons carried by said other carrier section.
 5. A rotary fluid engine as recited in claim 4 wherein said inlet ports are positionEd, angularly of said housing, to be uncovered by a pair of said pistons when said cranks are adjacent, but angularly offset from a dead center position relative to their links, and said exhaust ports are covered by the same pair of pistons before said cranks have turned 180 degrees from the first position.
 6. A rotary fluid engine as recited in claim 1 including a pair of said planetary gears, disposed diametrically opposite each other relative to said sun gear, each of said planetary gears carrying a pair of said cranks and links, the cranks of the respective planetary gears associated with each of said piston carrier sections being disposed 180* out of phase with each other.
 7. A rotary fluid engine as recited in claim 1 with the addition of means whereby said sun gear may be adjustably turned relative to said housing. 